The costumes Amy Adams wears in American Hustle (in theaters Dec.13) leave little to the imagination. You can blame (or thank) the ’70s for that.

In director David O. Russell’s sprawling period drama, Adams plays the part of conniving con woman Sydney Prosser. “She’s a woman from a small town who moves to New York to reinvent herself and she becomes the most sophisticated, confident dresser in Manhattan over the course of the film,” costume director Michael Wilkinson told EW. “She had like 50 [wardrobe] changes over this gradual shift.”

Adams’ character required her to be a bit of a chameleon, alternating between conservative ensembles and hyper-sexualized looks. “She’s playing a small time hustler who gets more sophisticated with her hustle,” explains Wilkinson. “It involves accents and costume changes and lots of flirtation and using her amazing physical appeal to get the situation where she wants it,” he adds.

But that swimsuit is another story.

“We found these amazing macramé one-piece bathing suits from the period at a rental house. But because they’re now 35 years old, they were discolored, they were stretched out,” says Wilkinson. “Any give they had had given up years and years ago.”

A droopy, discolored maillot was not going to cut it for this movie.

“We were lucky enough to find an Australian swimsuit manufacturer who was doing these reproductions of vintage styles. One of them was almost exactly a match for this reference suit we had, so we were just visited by the costume gods for that one,” Wilkinson says. “We got it in, she put it on and we knew that we had found the swimsuit.”

Get an inside look at the ’70s costumes and hairstyles in American Hustle and more stylish movies and TV shows in this week’s issue of Entertainment Weekly, on stands Friday.

American Hustle
  • Movie
  • 138 minutes